Statistics, badge counts and numbers in apps that help: step and active minutes counts on Fitbit. Streaks on Duolingo. Calendar counts on reproductive health apps. Delivery date estimates on Amazon (or time on Zomato).
Numbers that don’t help, that cause and in many cases are designed to cause anxiety: Instagram likes, Twitter notification counts that now include someone you know following someone else you may/not know, Reddit karma, unread counts on email/chat/Slack/news apps.